Early diagnosis is key to developing effective treatments, says local Alzheimer's expert
This article first appeared in the St. Louis Beacon, Dec. 29, 2010 - This year produced promising medical advances in the battle against Alzheimer's disease. First came word that scientists had come up with a new test for making more precise diagnoses of the disease. That news was followed this month by the announcement of a discovery of a relationship between an abnormal level of a plaque-forming substance in the brain and Alzheimer's.
Both developments are said to be important to long-term efforts to diagnose and treat Alzheimer's with new drugs even before the disease's symptoms become apparent in patients.
Dr. John Morris, a neurology professor and principal investigator at Washington University Medical School's Alzheimer's Disease Research Center, was among neurologists and other scientists who discussed a new test earlier this year for diagnosing the disease. Last week, following his first interview with the Beacon months earlier, Morris mentioned an important new discovery about Alzheimer's by his colleague, Dr. Randall Bateman, also of the Washington University Medical School.
Bateman has turned up a link between an abnormal level of a certain protein in the brain and the presence of Alzheimer's. The protein that scientists think abnormally accumulates very early in the Alzheimer's process is called amyloid-beta, commonly referred to as a-beta.
Researchers believe that either patients are making too much amyloid-beta or they cannot clear all of it from their brains. In either case, Bateman says, the buildup of a-beta is related to Alzheimer's.
The Bateman-led team compared a-beta levels of 24 patients, half of them having early Alzheimer's disease. They found that the clearance rates of the a-beta plaque-forming substance in Alzheimer's patients were 30 percent lower than rates for the 12 age-matched patients who didn't have Alzheimer's.
He says the finding shows that the disease is associated with disruption of the brain's ability to handle a-beta normally.
"These findings support the idea that impaired a-beta clearance is fundamentally linked to Alzheimer's disease," Morris says. He not only beamed about the finding but marveled at the fact that St. Louisans made possible research that he says has worldwide implications for finding a treatment for Alzheimer's.
"Without these research participants, acting altruistically and having samples taken," this discovery would not have been possible, he says.
Read the Beacon's earlier story below:
Word that researchers have developed a new, more accurate way of diagnosing Alzheimer's disease early has created hope that it will lead to improved treatment and perhaps even open up a path to a cure. But policymakers will have to deal with drawbacks as well.
The new test involves a spinal tap; doctors would analyze spinal fluid for Alzheimer's biomarkers. These biomarkers are present long before symptoms of the disease are evident.
At the moment, no cure is on the horizon. Nor are the current treatments particularly effective. With the stigma and the dread attached to the illness, patients may be reluctant to undergo an uncomfortable new test to provide an early diagnosis.
"Why detect any terrible disease early if you can't do anything about it?" asked Dr. John Morris, a neurology professor and principal investigator at Washington University Medical School's Alzheimer's Disease Research Center.
On the other hand, he says early diagnosis will help researchers make headway in treating Alzheimer's. Although the disease typically is found in people in their 70s and 80s, Morris says, it can occur as early as age 50.
The latest breakthrough brings added weight to a recommendation made last month when both the National Institute on Aging and the Alzheimer's Association called for early diagnosis and new treatments for Alzheimer's. The changes would be the first in a quarter century in the criteria for diagnosing the disease.
Morris predicts that recommendations on early diagnosis could become public policy within a few months because the case for doing so is compelling.
That's because Alzheimer's likely begins in the brain many years before a sufferer experiences its initial symptom: dementia. That provides time to develop therapies even if they do not currently exist.
"There may be a period of years, or even a decade, where the brain lesions are building up before they cause enough damage that people develop symptoms. We think you can have Alzheimer's disease without having dementia," Morris said.
"It's going to be years down the road, but if we can identify that pre-symptomatic stage with good accuracy, then that opens up the possibility of developing good treatment and interventions. We could actually intervene before any symptoms. The idea is that some day we will be looking at strategy to prevent the dementia caused by Alzheimer's disease."
He concedes, however, that controversy surrounds efforts to make a diagnosis early.
"That can cause difficulties because it hard to know if people are just merely forgetful because they are getting old," he says. "Do they have Alzheimer's or is something else going on, maybe a side effect of their medications, maybe they're depressed?"
But he says the potential for a misdiagnosis is offset partly by the fact that the new tests, such as the spinal fluid analysis, are more accurate. The biomarkers can also be detected through CAT scans and MRIs that tell doctors whether brain lesions associated with Alzheimer's actually are present.
Morris was asked whether he thought that insurers would pay for the additional testing, and whether the government would favor it as it tries to hold down health-care costs as it attempts to expand access to care.
"To be frank, none of that is worked out. Right now it's not being paid for by (an insurer). I'd have to say we're nowhere near that stage yet."
But he thinks society might eventually see the wisdom of testing. He says the U.S. now spends $160 billion a year to address problems associated with Alzheimer's.
"It will get worse because the population is aging," he says. "So I think it's really going to be cost effective to try to diagnose it early and prevent the disease."
Doing so, he says, will "save our country from being overwhelmed by people with Alzheimer's disease and a terrible public-health cost."
Funding for health reporting is provided in part by the Missouri Foundation for Health, a philanthropic organization whose vision is to improve the health of the people in the communities it serves.